Uni̇versi̇tà Della Calabri̇a

1.

UNİVERSİTÀ DELLA CALABRİA
Department of Chemistry and Chemical Technologies
MASTER’S DEGREE
CHEMİSTRY OF MOLECULAR AND NANO MATERİALS
Prof. Massimo LA DEDA
Synthesis of Gold Nanoparticles
Gülşah GÜLER
241115

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NANOPARTICLES:
• Nanoparticles are groups of atoms or molecules.
• These can be very type of sizes and shapes.
• Nanoparticles are structures with diameters between 1 and 100 nm.
Structure of Nanoparticles

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The synthesis of nanoparticles two main methods are produced with "top-down" and "bottom-up".

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Mechanical methods :
- cutting
- milling
Lithographic techniques:
- Photo Lithography
- Electron Beam Lithography
The breaking down of
the bulk material into
nanosized structures or
particles.

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The assembling single
atoms or molecules
into nanostructures
Photoreduction
Chemical reduction
- Microemulsion method
- Seed-mediated grow

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GOLD NANOPARTICLES:
Gold nanoparticles (AuNP) are the most stable metal nanoparticles.
Gold nanoparticles are colloids have particle size with their unique on surface plasmon resonance
(SPR).
Aqueous solutions of gold nanoparticles of different sizes.

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History Of Colloidal Gold:
Colloidal gold has been used since old times, especially in glass painting, for the its optical properties.
One of the famous historical examples of colloidal gold is the Lycurgus Cup produced in the 19th century.
So much methods have been developed to obtain gold nanoparticles from past to present.
Lycurgus Cup

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Synthesis Methods of Gold
Nanoparticles
Gold nanoparticles can be synthesized using so much methods.
Some common used synthesis methods for gold nanoparticles:
• Turkevich Method
• Brust-Schiffrin Method
• Seed-Mediated Growth Method

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Turkevich Method
With this method, monodisperse colloidal AuNPs are obtained as a result of the reaction of aqueous
tetrachloroauric acid with sodium citrate.
Sodium citrate moves as both a reducing agent and a stabilizing agent. This reaction yields spherical AuNPs in
size from 15 to 150 nm, depending on the first sodium citrate concentration.

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Brust-Schiffrin Method
With this method, smaller (2-6 nm) and more monodisperse stable AuNPs in size and shape are produced by biphasic
reduction by using tetraoctylammonium bromide (TOAB) as a phase transfer reagent and sodium borohydride (NaBH4)
as a reducing agent.

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Seed-Mediated Growth Method
This method involves the use of pre-formed gold nanoparticles as seeds for the growth of larger
nanoparticles.

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GEOMETRIC STRUCTURES OF
GOLD NANOPARTICLES

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Gold Nanospheres:
The seed growth method is used to obtain gold nanospheres.
The synthesis of gold nanospheres involves the reduction of gold ions in a solution, typically using a reducing
agent such as sodium citrate or sodium borohydride.

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Gold Nanorods:
The synthesis of gold nanorods involves a seed-mediated growth method.
In this method, gold seeds are prepared by reducing the chloroauric acid (HAuCl4) to sodium borohydride.
These seeds, which are prepared in the first place for growth, are then added to the aqueous surfactant
medium containing chloroauric acid (HAuCl4) and reducing agents and ascorbic acid and CTAB for the
growth stages.

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Absorption spectrum of gold nanoparticles in various sizes and shapes.

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Gold Nanocages:
Gold nanocages (particle size ~ 40-50 nm) are empty nanostructures that can be prepared with controllable
pores on the surface by the reduction-oxidation reaction between silver nanocubes and chloroauric acid
HAuCl4.
After obtaining silver nanostructures with controlled shapes, silver nanostructures are used as a template and
can be turned into Gold nanocages.

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Gold Nanoshells:
A common method for the preparation of gold nanoshells is the modification of the core surface with a
bifunctional ligand that increases the shell covering.

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Gold Nanostars:
Gold nanostars can be synthesized by the seed-mediated growth method.
The seed-mediated growth method involves the nucleation of gold seeds, followed by the controlled growth of
branches using a reducing agent and a growth solution.

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21.

https://dergipark.org.tr/tr/pub/hjbc
• They has researched at this research article investigated the synthesis parameters of gold nanoparticles and the
effect of experimental parameters on size and size distribution.
• The reduction reaction between tetrachloroauric acid and sodium citrate has used.
• At the end of the reduction reaction, gold nanoparticles with narrow size distribution has obtained.
• The initial gold concentration, trisodium citrate concentration and mixing rate has changed and their effects on
particle size and size distribution has investigated.

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• The optimal gold salt concentration, trisodium citrate concentration and mixing rate has found to be
0.06 mM, 0.17 mM and 450 rpm, respectively.
• They has found that initial gold salt concentration and trisodium citrate concentrations and mixing
rate are very important variables in the colloid nanoparticle synthesis.

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• They has synthesized gold nanoparticles by the citrate reduction method.
• The effects of different experimental parameters (Gold salt concentration, trisodium citrate concentration and
mixing rate) on it is size and size distribution at optimum pH and temperature has investigated.
• The optimal gold salt concentration, trisodium citrate concentration and temperature has found to be 20 mM, 1.5%
and 97 C respectively.

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• The morphology, size, and shape of synthesized gold nanoparticles has characterized by using
spectrophotometry, transmission electron microscopy (TEM) and zeta sizer.
• The colloidal gold nanoparticle of 15-20 nm size has obtained.

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• They has prepared Colloidal gold nanoparticles (spheres) from HAuCl4 containing aqueous solution by using Xray irradiation and by chemical reduction method.
• Gold nanorods has synthesized according to the seed-mediated growth method.
• The colloidal gold nanoparticles has characterized by using transmission electron microscopy, X-ray diffraction,
and UV-VIS absorption spectroscopy.
• They has found that the concentration of the precursors affects the size of the nanoparticles.

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• Gold nanorods has synthesized according to the seed-mediated growth method with two steps.
• The effect of silver acetate and CTAB on formation of gold nanorods has studied.

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https://doi.org/10.1016/j.materresbull.2015.12.026
• Gold nanoparticles has synthesized by NaBH4 reduction method.
• The particle size, size distribution and morphology has investigated.
• Particle size has determined both experimentally as well as theoretically. Particle size had determined by
different techniques can be correlated for monodisperse particles and an excess of reducing agent has found to cause
an increase in particle size.

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www.sciencedirect.com/journal/results-in-chemistry
• Gold nanoparticles has prepared with two aqueous extracts of Ziziphus spina-christi leaves and Cordia myxa L.
leaves and has identified using TEM, FE-SEM and AFM.
• The ability of gold nanoparticles as an anti-breast cancer agent has tested against MCF-7 cell line in synergistic
with near-infrared radiation (NIR) at 808 nm.
• They have found that radiation enhances the properties of gold nanoparticles as a cancer treatment by converting
the absorbed light into heat in a short time through a series of non-radiative processes.

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References
• YÜCEL O. (2018). Synthesis, Characterization And Investigation Of Drugrelease Behaviour Of Gold
Nanoparticles (Msc Thesis). Istanbul University, Institute Of Graduate Studies In Science And
Engineering
• Annalise A. (2019)Synthesis And Characterization Of Gold Nanoparticles, Polıtecnıco Of Turın,
Master Course In Materials Engineering
• SAYAR F. (2010). Production Of Nanoparticles And Their Application In Nanomedicine, Doctoral
Thesıs, Hacettepe University